Two California centers were temporarily closed in the US, where they carried out mass vaccination against coronavirus with a drug company Johnson & Johnson. The reason is an adverse reaction identified in 18 vaccinated citizens, the Wall Street Journal reported.

Patient symptoms ranged from dizziness to nausea. Four people with side effects were hospitalized for examination. In total, more than 2,300 people were vaccinated at the center before closing.

A Johnson & Johnson spokesman said the company is closely monitoring any reports of side effects caused by the vaccine.